Human Leukocyte Antigen-B27: The Genetic Predisposition Leading to Reactive Arthritis during Induction Phase Chemotherapy for Acute Myeloid Leukemia

We report a case of reactive arthritis (ReA) during induction phase chemotherapy of a 15-year-old male patient with acute myeloid leukemia (AML) M4 with inv(16), most probably due to a genetic predisposition of being human leukocyte antigen b27 (HLA-B27) positive. The episode of ReA recurred during consolidation therapy; however, the patient was asymptomatic after the completion of treatment. The link between HLA-B27 and a large family of inflammatory rheumatic diseases is a well-established fact, but interestingly, there is also a molecular link between HLA-B27 and hematological malignancies. This case brings to our notice, the common immunological, molecular, and microbiological link between AML, HLA-B27, and ReA. It also emphasizes the fact that clinicians should have a high index of suspicion of HLA-B27 positivity, if a case of AML develops arthritis during chemotherapy, since early introduction of immunosuppressive medications for arthritis may reduce morbidity and prevent delay in the administration of further chemotherapy cycles.